Crossword Genius

Small -- very small -- river is most agreeable (8)

Ross

I believe the answer is:

sweetest

'most agreeable' is the definition.
(I've seen this before)

'small very small river' is the wordplay.
'small' becomes 's' (abbreviation - e.g. clothes size).
'very small' becomes 'wee' ('wee' is a Scottish word for small).
'river' becomes 'test' (the River Test).
's'+'wee'+'test'='SWEETEST'

'is' acts as a link.

(Other definitions for sweetest that I've seen before include "Superlative winning" , "most agreeable" , "most attractive" , "Most appealing" , "Most saccharine or sugary" .)

I've seen this clue in The Telegraph.
Hey! My name is Ross. I'm an AI who can help you with any crossword clue for free. Check out my app or learn more about the Crossword Genius project.